When Casey and Mia have their first fight as an engaged couple, Casey implements his plan that stops all arguments cold. In an effort to help, Maddie decides to show them how arguing can actually be healthy for a relationship, but ends up exposing a fault in her own nine-year relationship with Ben. Meanwhile, the longtime married Vicky and Joel quietly resolve their arguments by simply hiding each other's things.

It's Halloween, which is also the date of Maddie's birthday. Because Maddie feels like she can never have a real birthday -- since the holiday always steals the spotlight -- Mia and Casey offer to give her a Halloween-free party at their new home, the renovated firehouse. Ben, however, wasn't listening when Maddie told him what she wanted for a gift, so Joel tells him about what he does whenever he messes up. Meanwhile, Maddie and Vicky warn Mia that couples living together shouldn't look behind each other's "curtain," for fear they might learn things they should never know about each other; when Mia finds a mysterious videotape among Casey's things, she wonders what it might reveal behind his curtain.

Joel and Ben accompany Casey on a road trip to Vermont to help him move his stuff out of storage. Ben looks at the trip as an opportunity to bond with Casey; but Joel sees the road trip as his annual chance to go off -- way off - of his salt-free diet. Meanwhile, the Putney women organize Mia's baby shower, and Casey's hard-to-please mother, the earthy but rather quirky Ariel, comes for a visit. Mia goes out of her way to be accepted by her future mother-in-law, but things get heated between Vicky and Ariel when both want their grandchild to call them "Nana".

Mia and Casey are excited when Maddie gets them a meeting with one of the top wedding planners in the city -- the charming but very expensive Lorraine Ashley. But the too-good-to-be-true arrangement turns awkward when it looks like Lorraine is trying to upstage the couple's pending nuptials. Meanwhile, Ben realizes that he has been with Maddie for so long that his "flirting muscle" has gone soft.

This Thanksgiving, everyone but Vicky is relieved when her oven breaks down. For once, the rest of the family can enjoy a normal Thanksgiving dinner and won't have to endure one of her unsavory concoctions -- such as maple syrup turkey stuffed with shrimp and raisins. And while spending the holiday at Maddie's and Ben's apartment, Mia accidentally finds her late grandmother's presumably stolen ring hidden in their linen closet... Now the unmarried couple has some explaining to do.

Mia and Maddie know their parents will give them an avalanche of guilt if they don't uphold the Putney family Christmas tradition of spending the holiday together at their lake house. When Maddie finds out Mia and Casey are using their pregnancy as an excuse, she tells Vicky and Joel her own tall tale to keep from having to go.

When Mia accuses Ben of ripping her favorite pair of jeans, she drags him to the store, where he has to break the tough news to Mia it's time for pregnancy pants. Meanwhile Joel decides to get himself into shape after he finds out he's ranked last in Vicky and her girlfriends' fantasy husband draft website, and Maddie goes to extreme lengths to impress Casey with her high regard for the U.S. Postal Service.

After parents-to-be Mia and Casey adopt a cat, the pediatrician tells them they shouldn't have a stray animal around the baby. Maddie and Ben enter into a spirited competition with Vicky and Joel, all under the impression that if one of them takes in Mr. Meow-gi, then Mia and Casey will name that couple as the baby's guardian.

Casey has big plans for his first Valentine's Day with Mia, but Ben and Joel tell him that their rule is to never buy expensive Valentine's Day gifts for their ladies because doing so would set a costly precedent. Casey goes ahead with his plans anyway, and Ben realizes that he too wants to show Maddie how he feels. When Joel finds out, he decides to compete with them no matter the cost - and gets singer/pianist Michael Feinstein to perform.

The job interview-bound Casey, unaware that bad luck always follows the wearer of a particular leather jacket, borrows it without telling anyone. Everyone recalls their own bad experience while wearing the jacket, including Ben, who accidentally dropped a blanket on New York Yankee outfielder Nick Swisher when he was trying to catch a fly ball.

More than anything, Ben wants his name on a shamrock posted on the wall of his favorite bar. But his dream may be dashed when he learns that the bar's new owner is New York Yankee outfielder Nick Swisher. Ben can only hope that Nick won't remember that it was he who accidentally dropped a blanket on him during a baseball game, preventing Nick from making a fly ball catch. Meanwhile, Mia and Maddie communicate in their own secret language their reluctance to accompany Vicky to a charity event.

Casey finds out that his ex-girlfriend wants to pick up the couch that she lent him before their breakup - the same couch that Mia and Casey are currently using. Since the Putney girls are known to be the jealous type, Ben assures Casey that he'll come up with the perfect plan to help him get rid of it without Mia knowing the real reason. Meanwhile, Maddie updates Vicky and Joel's wills, but finds they won't take her professional efforts seriously.

Maddie is ecstatic when she's told that she has made partner at her law firm. But just as soon as she tells everyone about her promotion, she gets laid off and, to save face, tells everyone she quit because she got a better job. Meanwhile, Vicky gives Mia and Casey a children's book passed down through the generations. Upon closer scrutiny, they parents-to-be wonder if there's a hidden, negative message between the lines.

On the eve of Mia and Casey's engagement party, Maddie gets a feeling that the oh so romantic and charming story Mia has been regaling everyone with about how she and Casey met isn't true; and Mia starts to doubt her sister's story that she and Ben met while building houses for the poor. Meanwhile, Vicky and Joel, who have always said they met chasing a foul ball at a baseball game, have the engagement party at their country club and realize they can save some money at the same time by promoting Joel's campaign for the club's treasurer.

During their "first wedding dance" class, expert dancer Casey realizes that Mia has two left feet on her. He purposely tanks his moves so he can let his bride-to-be look better, and asks Phillip, the dance instructor, to keep his secret. Also, Ben runs into the legendary Larry King at his hotel and asks him for advice on how to handle a spat he had with Maddie about Vicky and Joel - but plays down what he really said about them.

Once the very pregnant Mia realizes her condition won't let her take part in all of her wedding festivities, she and Casey decide to reschedule the wedding until after the baby is born. As they go about trying to get their deposits back, the bridal shop manager refuses to refund Joel's money. Also, Ben finds that out that Joel is trying to keep from crying while preparing his wedding toast. He tries everything possible to make Joel shed some tears to get him back for the time Ben was ridiculed for crying when his childhood dog died.

While in labor, Mia and Casey decide that they should be married before baby Charlie comes into the world. The rush is on to make the wedding happen, as Casey and Ben dash to City Hall for the marriage license; Maddie puts herself in charge of finding an authorized person to perform the ceremony; and Vicky and Joel hurry to the hospital's gift shop to find the "something old, something new, something borrowed, something blue" items.